[boyt911sc]

Originally, the ‘76~’79(?) CIS air boxes came without the “spider plumbing” found in the late SC’s (‘81~’83). Subsequently, the new replacement CIS airboxes both 34-mm and 38-mm ID now have the “spider plumbing” installed already. Not exactly sure when it was first introduced because I have a couple ‘79 CIS airboxes with the spider on them.

My ‘78 SC still has the old original airbox without the spider plumbing. And will replace it next time I have the motor out. So when you decide to replace your old air boxes, make sure you get the one with the “spider plumbing”.

However, you cannot perform a CSV flow test to airboxes with “spider” in situ. The CSV has to be removed from its mounting for visual test.

Tony